<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title>循环</title>
	</head>
	<body>
		<button onclick="a()">点击</button>
		<script>
			function a() {
				for (var j = 10; j > 0; j--) {
					for (var i = 0; i < j; i++) {
					document.write("❤");
					}
				document.write("<br/>");
				}
		}
		</script>
	</body>
</html>
